The proper control of blood clotting is essential to the health of a mammal. Both the insufficient clotting that leads to bleeding is a serious problem for some individuals, and the increased tendency to clot resulting in stroke, myocardial infarction, or deep vein thrombosis, are also dangerous to the individual.
Blood coagulation is a complex defensive mechanism. Blood clotting is essential to prevent hemorrhage from damaged blood vessels. A thrombus is a clot in the blood vessels. Blood does not normally clot in the vascular system, since thrombin is present in the inactive form, prothrombin, which becomes activated to thrombin when blood escapes due to injury or is withdrawn from the blood vessels.
Thrombi can form in response to changes in the blood vessel wall to which platelets adhere. The final stage of clotting process is turning of fibrinogen, which is soluble and optically invisible, into fibrin which is insoluble. The fibrin separates as long fibers or threads, which are extremely adhesive. These threads stick to each other, blood cells, tissues, and foreign substances to form a three dimensional network or clot. The formation of a clot is the final event in the blood coagulation cascade. Fibrinogen plays a key role in the final stage of clotting
There is another important phenomenon associated with blood fibrinogen: In the presence of fibrinogen and globulin, red blood cells tend to form aggregates known as rouleaux. An abundance of fibrinogen has a greatest impact on the elevation of aggregation rate in blood.
Some methods for treating and/or measuring blood flow are exemplified by the following publications:
U.S. Pat. No. 5,869,044 to Tomaru et al., discloses a method for the treatment or prophylaxis of ischemia-reperfusion injury including administration of batroxobin as an effective component;
U.S. Pat. No. 6,322,525 to Kensey et al., discloses a method of analyzing data form a circulating blood visocometer for determining absolute and effective blood viscosity;
U.S. Pat. No. 6,551,266 to Davis, Jr., describes rheological treatment methods and related apheresis systems for removing certain rheologically active elements from the blood of a patient;
US 2004/0180051 to Suzuki, discloses blood rheology improving agents including an antibody against human tissue factor (human TF);
US 2004/0090614 to Greco discloses spectral analysis of light scattered from clotting blood. The method comprises irradiating a specimen with light and recording light reflected into the hemisphere of the irradiating beam. The time course of the reflected light intensity is divided into distinct regions, each of which is fitted to a mathematical formula. The parameters from these formulae are used to assign values to each specimen. The assigned values identify disease states and quantify the effects of drugs on clotting.